Approximately 4000 patients have undergone operation for acquired and congenital heart disease in this clinic. Pre- and postoperative hemodynamic, clinical assessment and long-term followup has generated valuable data concerning survival, complications, and functional improvement following operative intervention. Individuals who have undergone single or multiple valve replacement (n equals 1000) are being used as a pilot cohort of patients in this study. Survival, functional class improvement, hemodynamic results, specific incidences of emboli, prosthetic malfunction, infection, and reoperation are being analyzed. Autopsy findings or clinical cause of death is also being recorded.